In the first two weeks since the election, President-elect Barack Obama has broken with a tradition established over the past eight years through his controversial use of complete sentences, political observers say.

Millions of Americans who watched Mr. Obama’s appearance on CBS’s 60 Minutes on Sunday witnessed the president-elect’s unorthodox verbal tic, which had Mr. Obama employing grammatically correct sentences virtually every time he opened his mouth.

But Mr. Obama’s decision to use complete sentences in his public pronouncements carries with it certain risks, since after the last eight years many Americans may find his odd speaking style jarring.